Project Summary The ability to heal oral wounds is an important aspect of an individual's health and is negatively affected by diabetes. Surprisingly little is known about the impact of diabetes on the molecular events of oral wound healing. Our recently published studies demonstrate that activation of the transcription factor forkhead box O1 (Foxo1) in keratinocytes plays important but surprisingly, opposite roles in re-epithelialization of wounds in diabetic and normoglycemic animals. Preliminary Data shows that keratinocytes promote connective tissue healing under normal conditions through a FOXO1 dependent mechanism but inhibit connective tissue formation in diabetic wounds. The goal of this proposal is to unravel the molecular mechanisms through which FOXO1 differentially activates keratinocytes to promote or inhibit connective tissue healing depending upon normoglycemic or diabetic conditions. The results will establish how FOXO1 may be an important therapeutic target in promoting wound healing in diabetes. Aim 1 will establish mechanisms through which two key FOXO1 downstream targets (TGF?1 and MMP9) are inversely modulated by diabetic conditions in vitro (high glucose and advanced glycation end products) in gingival keratinocytes and compare the results with epidermal keratinocytes. Aim 2 will establish mechanisms through which keratinocytes enhance connective tissue healing in a FOXO1 dependent manner in normoglycemic wounds but inhibit it in diabetic wounds. These studies will focus on the impact of FOXO1 in organizing the expression of factors by keratinocytes that stimulate fibroblasts and endothelial cells in normal conditions but fail to do this in diabetic conditions. The goal of Aim 3 is to carry out translational studies and establish functional to rescue diabetic healing. They will determine whether modulation of FOXO1 downstream targets reverses diabetes impaired gingival and dermal healing and whether FOXO1 is a good therapeutic target to improve diabetic healing. The proposed studies are strongly supported by Preliminary Data, will definitively test whether FOXO1 plays a central role in impaired diabetic oral wound healing and will provide the basis for future studies by establishing whether its inhibition has therapeutic value.